The Cypress Testing Framework Code has been included (forgotten to remove?) in 16.0.2 release package. Now the integrity check fails.
I had the problem also, remove the folder and it works.
This problem has already been reported by several people in a different thread. Sometimes it is worse to use the search function of this forum first before opening a new thread
Then you now have the reason, why i changed to a regular server: i installed ubuntu with desktop for setup with oracle virtual box. I then installed ubuntu server for my nextcloud in a virtual machine. This vm you can copy for makeing a backup before testing updates or changes. But! If you have synced your data complete with a client, you can backup you contacts and diary entries on your phone, set up nextcloud pi from ground a copy back your datas from the sync client and then contacts and schedules. In past, i often did that, when major changes hapened( new mariadb version, new php version etc.)